WO2017001307A1

WO2017001307A1 - Novel substituted aminothiazolopyrimidinedione for the treatment and prophylaxis of virus infection

Info

Publication number: WO2017001307A1
Application number: PCT/EP2016/064771
Authority: WO
Inventors: Lisha Wang; Hongying Yun; Xiufang ZHENG
Original assignee: F Hoffmann La Roche AG; Hoffmann La Roche Inc
Current assignee: F Hoffmann La Roche AG; Hoffmann La Roche Inc
Priority date: 2015-06-30
Filing date: 2016-06-27
Publication date: 2017-01-05
Anticipated expiration: 2017-12-30
Also published as: CN107820498B; JP2018527309A; HK1251554A1; EP3317289A1; CN107820498A; US10590146B2; US10975098B2; EP3317289B1; US20180118763A1; US20200231600A1; JP6839104B2

Abstract

The present invention relates to compounds of formula (I), wherein R¹ to R⁴ are as described herein, and their pharmaceutically acceptable salts, enantiomers or diastereomers thereof, and compositions including the compounds for use in the treatment of viral infections.

Description

Novel substituted aminothiazolopyrimidinedione for the treatment and prophylaxis of virus infection

The present invention relates to novel substituted aminothiazolopyrimidinedione and their corresponding derivatives that have Toll-like receptor agonism activity and their prodrugs thereof, as well as their manufacture, pharmaceutical compositions containing them and their potential use as medicaments.

FIELD OF THE INVENTION

The present invent ion relates to compounds of fo mula (I) and ( la).

wherein R.¹ to R are described below, or pharmaceutical ly acceptable salt, enantiomer or diastereomer thereof.

Toll-l ike receptors (TLRs) recognize a wide range of conserved pathogen-associated molecular patterns (PAMPs). They play important roles of sensing invading pathogens and subsequent initiation of innate immune responses. There are 10 known members of the TLR family in human, which are type I transmembrane proteins featuring an extracellular leucine- ich domain and a cytoplasmic tail that contains a conserved Toil/ interleukin (IL)-l receptor (TIR) domain. Both TLR7 and TLR8 are localised intracellular!}' to the endosomal membrane. They are phylogenet ically similar and are both capable of recognizing single-stranded RNA (ssRNA) and short double-stranded RNA, due to their roles in sensing different viral pathogens. TLR7 and TLR also can be st imulated w ith oligoribonucleotides and a variety of synthetic chemical agonists such as imidazoquinolines. Following binding of ssRNA or small molecules to TLR7 and/or TLR8, the receptor in its dimcrized form is believed to undergo a structural change leading to the subsequent recruitment of adapter proteins at its cytoplasmic domain, including the myeloid different iat ion primary response gene 88 (MyD88). Following the init iation of the receptor signalling cascade via the MyD88 pathway, cytoplasmic transcript ion factors such as interferon regulatory factor 7 ( IRF-7) by TLR7 and/or nuclear factor kappa B (NF- Β) by TLR8 are activated. These transcription factors then translocate into the nucleus and initiate the activat ion of various genes, e.g., type I interferon (IFN-a and I FN-β) and other pro -inflammatory cytokine genes, e.g. I I. -6, TN Fa et al. TLR8 is known to be primarily expressed in monocytes/macrophages and myeloid dendritic cells (mDCs), while TLR7 is predominately expressed in plasmacytoid DCs (pDCs) and, to some extent, in B cells and monocytes macrophages. The TLR7 or TLR8 selective agonist can activate different cell types and induce different immune response. However, a TLR7/8 dual agonist has the potential to activate induce broad immune response. Because of their efficiency in act ivat ing immune responses, the TLR7 and/or TLR8 agonists are being investigated for a broad variety of applications, including ant iviral and ant itumor therapies and use as a vaccine adjuvant.

Several TLR7 and/or TLR8 agonists have been used for therapeutic purposes. Imiquimod (ALDARA™) is a U.S. FDA approved TLR7 agonist drug for topical use to treat skin lesions due to human papillomavirus infect ion. The TLR7/8 dual agonist Rcsiquimod (R-848) and the TLR7 agonist 852 A arc under evaluating for treating human genital herpes and chemotherapy- refractory metastatic melanoma, respectively. ANA773 is an oral pro-drug TLR7 agonist, developed for the treatment of patients with chronic hepat it is C virus ( HCV) infect ion and chronic hepatitis B infect ion. GS-9620 is an orally available TLR7 agonist. A phase lb study demonstrated that treatment with GS-9620 was safe, well tolerated and resulted in dose- dependent ISG 1 5 mRNA induct ion in pat ients with chronic hepat it is B (E. J. Gane et al, Annu Meet Am Assoc Study Liver Dis (November 1 -5, Washington, D.C.) 201 3, Abst 946). More recently, VTX-2337, a highly select ive TLR8 agonist, discovered by VentiRX Pharmaceut icals (WO 200702461 2 ), has been used in treatment of human head and neck cancer patients. (D. W. Northfelt et al, Clin Cancer Res 2014, 20, 3683-3691 . ) Although quite a few TLR7 agonists have been reported in the last decade, and only few TLR8 or TLR7/8 dual agonists were reported, there is still high unmet clinical need for developing potent and safe TLR7 and/or TLR8 agonists as new antiv iral and antitumor treatment to offer more therapeutic solutions or replace existing partly effect ive treatments.

SUMMARY OF THE INVENTION

The present invent ion prov ides a series of novel 3-substituted 5 -am i no-6//-t h iazo lo [4,5- </] pyr i m i d i ne-2 , 7-d io ne compounds, that have Toll-like receptor agonism activity and their prodrugs. The invent ion also provides the bio-activity of such compounds to induce SEAP level increase by activat ing Toll-like receptors, such as TLR7 and/or TLR8 receptors, the metabolic conversion of prodrugs to parent compounds in the presence of human hepatocytes, and the therapeutic or prophylactic use of such compounds and their pharmaceutical composit ions comprising these compounds and their prodrugs to treat or prevent diseases such as cancer, autoimmune diseases, inflammat ion, sepsis, allergy, asthma, graft rejection, graft -versus-host disease, i m m u no d e fi c i e n c i e s , and infect ious diseases like HBV or HCV. The present invent ion also provides compounds with superior activity.

The present invent ion relates to novel compounds of formula (I) and ( la),

wherein

R¹ is H, C| <,alky , C ? -cyc!oalky or phenylCi <,alkyl, said pheny!Ci <,alkyl being unsubstituted or substituted with one to three substituents independently selected from C| <,alkyl and halogen;

R² is H or Ci-ealkyl;

R³ is Ci.₆alkyi;

R⁴ is C _M,alkyl;

or pharmaceut ically acceptable salt, enantiomer or diastereomer thereof. Thc invention also relates to their manufacture, medicaments based on a compound in accordance with the invention and their production as well as the use of compounds of formula (I) or ( la) or their prodrugs, thereof as TLR7 and/or TLR8 agonist. Accordingly, the compounds of formula ( I ) and ( la) are useful for the antiviral treatment or prophylaxis, such as HBV and/or HCV infect ion, as well as ant itumor treatment, with Toll-like receptors agonism.

DETAILED DESCRIPTION OF THE INVENTION Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Furthermore, the follow ing definit ions are set forth to illustrate and define the meaning and scope of the various terms used to describe the invention. DEFINITIONS

As used herein, the term "C_halky!" denotes a saturated, linear or branched chain alky] group containing 1 to 6, particularly 1 to 4 carbon atoms, for example methyl, ethyl, n-propyi, isopropyl, n-butyl, /.w-butyl, /tvY-butyl and the like. Particular "C_halky!" groups are methyl, ethyl and n-propyl. The term "(\ -cycloalkyp, alone or in combination, refers to a saturated carbon ring containing from 3 to 7 carbon atoms, particularly from 3 to 6 carbon atoms, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl. cycloheptyl and the like. Particular "CY

₇cycloalkyl" group is cyclopropyl.

The term "enantiomer" denotes two stereoisomers of a compound which are non- superimposable mirror images of one another.

The term "diastereomer" denotes a stereoisomer with two or more centers of chirality and whose molecules are not mirror images of one another. Diastereomers have different physical properties, e.g. melt ing points, boiling points, spectral properties, and react iv it ies.

The term "pharmaceutically acceptable salts" denotes salts which are not biologically or otherwise undesirable. Pharmaceutically acceptable salts include both acid and base addition salts. Thc term "pharmaceutically acceptable acid addition salt" denotes those pharmaceutically acceptable salts formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, carbonic acid, phosphoric acid, and organic acids selected from aliphat ic, cycloaliphatic, aromat ic, araliphat ic, heterocyclic, carboxylic, and sulfonic classes of organic acids such as formic acid, acetic acid, propionic acid, giycoiic acid, gluconic acid, lactic acid, pyruvic acid, oxalic acid, malic acid, maleic acid, maloneic acid, succinic acid, fu marie acid, tartaric acid, citric acid, aspart ic acid, ascorbic acid, glutamic acid, anthranilic acid, benzoic acid, cinnamic acid, mandel ic acid, embonic acid, phenylacet ic acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, and salicyclic acid.

The term "pharmaceut ically acceptable ba.se addit ion salt" denotes those pharmaceut ically acceptable salts formed wit h an organic or inorganic base. Examples of acceptable inorganic bases include sodium, potassium, ammonium, calcium, magnesium, iron, zinc, copper, manganese, and aluminum salts. Salts derived from pharmaceutically acceptable organic nontoxic bases includes salts of primary, secondary, and tertiary amines, subst ituted amines including naturally occurring subst ituted amines, cyclic amines and basic ion exchange resins, such as isopropylaminc, trimethylaminc, diethylamine, triethy!amine, tripropylamine, ethanolamine, 2-diethylaminoethanol, tri met ha mine, d icyc lo hex via m i ne, lysine, arginine, hist idine, caffeine, procaine, hydrabamine, choline, bet a inc. ethylcnediaminc, glucosamine, methylglucamine, theobromine, purines, piperizine, piperidine, N-cthylpiperidine, and polyamine resins.

Compounds of the general formula (I) or ( la) and their prodrugs which contain one o several ehiral centers can either be present as racemates, diastereomeric mixtures, or optically active single isomers. The racemates can be separated according to known methods into the enant iomers. Particularly, diastereomeric salts which can be separated by crystallizat ion arc formed from the racemic mixtures by react ion with an optically act ive acid such as e.g. D- or L- tartaric acid, mandelic acid, malic acid, lact ic acid or camphorsulfonic acid.

The compounds of the invent ion may exhibit t he phenomenon of tautomerism. While the formula drawings cannot expressly depict all possible tautomeric forms, it is to be understood they are intended to represent any tautomeric form of the depicted compound and are not to be l imited merely to a specific compound form depicted by the formula drawings. For example, it is understood for formula ( I I ) that regardless of whether or not the substituents arc shown in their enol or their keto form, they represent the same compound (as shown in the example below ).

R_x refers to any feasible substituent.

Some of the compounds of the present invention may exist as single stereoisomers (i.e., essentially free of other stereoisomers), racemates, and/or mixtures of enantiomers and/or diastereomers. All such single stereoisomers, racemates and mixtures thereof are intended to be within the scope of the present invention. Preferably, the inventive compounds that are optically active are used in optically pure form. As generally understood by those skilled in the art, an optically pure compound having one chiral center (i.e., one asymmetric carbon atom) is one that consists essentially of one of the two possible enantiomers (i.e., is enantiomericaliy pure), and an optically pure compound hav ing more than one chiral center is one that is both

diastereomericaiiy pure and enant iomerical iy pure. Preferably, the compounds of the present invent ion are used in a form that is at least 90% optical ly pure, that is , a form that contains at least 90% of a single isomer (80% enantiomeric excess ("e.e.") or diastereomeric excess ("d.e.")), more preferably at least 95% (90%> e.e. or d.e. ), even more preferably at least 97.5% (95%> e.e. or d.e.), and most preferably at least 99%> (98 > e.e. or d.e.). Additionally, compounds of formula (I) and ( la) and their prodrugs, formula ( I I ) and (Ila), and other compounds of the invention are intended to cover solvated as well as unsolvated forms of the identified structures. For example, formula (I) or ( la) includes compounds of the indicated structure in both hydrated and non- hydrated forms. Other examples of solvates include the structures in combination with

isopropanoi, ethanol, methanol, DM SO, ethyl acetate, acetic acid, or ethanolamine.

The term "prodrug" denotes a form or derivat ive of a compound which is metabolized in vivo, e.g., by biological fluids or enzymes by a subject after admin istration, into a

pharmaco logical 1 y act ive form of the compound in order to produce the desired pharmacological effect. Prodrugs are described e.g. in "The Organic Chemistry of Drug Design and Drug Action", by Richard B. Silverman, Academic Press, San Diego, 2004, Chapter 8 Prodrugs and Drug Delivery Systems, pp. 497-558. "A pharmaceutically active metabolite" is intended to mean a pharmacologically activ e product produced through metabolism in the body of a specified compound or salt thereof After entry into the body, most drugs arc substrates for chemical react ions that may change their physical properties and biologic effects. These metabolic conversions, which usual ly affect the polarity of the compounds of the invention, alter the way in which drugs are distributed in and excreted from the body. However, in some cases, metabolism of a drug is required for therapeutic effect.

The term "therapeutically effect iv e amount" denotes an amount of a compound or molecule of the present inv ent ion that, when administered to a subject, (i) treats or prevents the particular disease, condit ion or disorder, (ii) attenuates, ameliorates or eliminates one or more symptoms of the particular disease, condit ion, or disorder, or (iii) prev ents or delays the onset of one or more symptoms of the particular disease, condit ion or disorder described herein. The therapeutically effective amount will vary depending on the compound, the disease state being treated, the severity o f the disease treated, the age and relative health of the subject, the route and form of admin istration, the judgement of the attending medical or veterinary pract it ioner, and other factors.

The term "pharmaceut ical composition^"' denotes a mixture or solution comprising a therapeutically effect ive amount of an active pharmaceutical ingredient together with

pharmaceut ically acceptable excipients to be administered to a mammal, e.g., a human in need thereof.

TLR7 AND/OR TLR8 AGONIST

The present invention relat es to a compound of formula (I),

wherein R ¹ is H, C^'u.alkyl. C 5-?cycloalkyl. or phcnylC^'u.alkyl. said phenylC ,alkyl being unsubstituted substituted with one to three substituents independently selected from C, <,alkyl and halogen;

R - is H or C ,alkyl;

R³ is Ci.₆alkyi;

R⁴ is C ,alkyl;

or pharmaceut ically acceptable salt, enantiomer or diastereomer thereof.

Another embodiment of present invention is relates to (ii) a compound of formula (la),

wherein

R¹ is H, C' M.alkyl, (\ -cycloalkyl or phenylCi <,alkyl, said phenylC ,alkyl being unsubstituted substituted with one to three substituents independently selected from C .alkyl and halogen;

R is 1 1 or C ,alkyl;

R³ is Ci_₆alkyi;

R⁴ is C_halky!;

or pharmaceut ically acceptable salt, enantiomer or diastereomer thereof. A further embodiment of present invention is (iii) a compound of formula (I) or ( la), wherein

R¹ is I I, methyl, propyl, cyclopropyl, benzyl, fiuorobenzyi, chlorobenzyl, fluorochlorobenzyl or methylbenzyi;

R is H or methyl;

R³ is methyl;

R⁴ is ethyl;

or pharmaceutically acceptable salt, enantiomer or diastereomer thereof. A further embodiment of present invention is (iv) a compound of formula (I) or ( la), wherein R ¹ is 1 1, C_halky! or phenylCi ^alkyh or pharmaceut ically acceptable salt, enant iomer or diastereomer thereof.

A further embodiment of present invention is (v) a compound of formula (I) or ( la), wherein R¹ is 11, methyl or benzyl; or pharmaceutically acceptable salt, enant iomer or diastereomer thereof. A further embodiment of present invention is (vi) a compound of formula (I) or ( la), wherein R is 11 ; or pharmaceut ically acceptable salt, enant iomer or diastereomer thereof.

Another embodiment of present invent ion is that (vii) part icular compounds of formula (I) or (la) are the following:

5 -Amino-3-[(2/?.3S,5.S^")-3-[( I S)- 1 -aminocthyl] -5-[ ( 15)- l -hydroxypropyl jtetrahydrofuran-2-yl ] - 6H-t h iazo !o [4,5 -J] pyrim id inc-2 ,7-d ione ;

5-amino-3-[(2/?,3S,5S)-3-[( \ R )- \ -aminoethyl ]-5-[( 1 S)- 1 -hydroxypropyl]tctrahydrofuran-2-yl]-

6//-thiazolo[4,5-(/]pyrimidine-2,7-dione;

5-Amino-3-[(2/?,3S,5S)-5-| ( 15)- 1 -hydroxypropyl ]-3-[ ( } R )- \ - (methylamino)ethyl]tetrahydrofuran-2-yl]-6H-thiazoio[4,5-<i]pyrimidine-2,7-dione;

5-Amino-3-[(2i?,35,55)-5-[(l₁S)-l-hydroxypropyl]-3-[(li?)-l- (propyiamino)ethyi]tetrahydrofuran-2-yl]-6H-thiazolo[4,5-(i]pyrimidine-2,7-dione;

5-Amino-3-[ (2/?,3S,55)-3-[( 1 /?)- 1 -(cyclopropylamino )ethyl ]-5-[( 15)- 1 - hydro xypropyl]tetrahydrofliran-2-yl]-6H-thiazolo[4,5-d]pyrimidine-2,7-dione; 5-Amino-3-[ (2/?,35,5S)-3-[ ( 1 /?)- 1 -( benzylamino )ethyl j-5-[( 15)- 1 - hydroxypropyl ]tetrahydrofuran-2-yr

5-Amino-3-( (2/?,3S,55)-5-[ ( 1 S)- 1 -hydroxypropyl]-3-[( 1 S)- 1 -

(methylamino)ethyl]tetrahydrofuran-2-yl]-6H-thiazoio[4,5-J]pyrimidine-2,7-dione;

5-Amino-3-[ (2 ?.3S.5S)-3-[( 1 ^)- 1 -(benzylamino )ethyl j-5-[ ( 15)- 1 - hydroxypropyl ]tetrahydrofuran-2-yl]-6/7-thiazolo[4,5-J]pyrimi and

5-Amino-3-[(2/?,3S,5S)-3-[ ( l / - l -(dimethylamino )ethyl]-5-[( 1 S)- 1 - hydroxypropyl ]tetrahydrofuran-2-yl ]-6//-thiazolo[4,5-J]pyrim id ine- or pharmaceutically acceptable salt, enantiomer or diastereomer thereof.

SYNTHESIS

The compounds of the present invention are prepared by any conventional means. Suitable processes for synthesizing these compounds as well as their starting materials are provided in the schemes below and in the examples. All subst ituents, in particular, R¹ to R⁴ are as defined above unless otherwise indicated. Furthermore, and unless explicitly otherwise stated, all reactions, reaction conditions, abbreviat ions and symbols have the meanings well known to a person of ordinary skill in organic chemistry.

Scheme 1 :

Compound of interest I l lin can be prepared according to Scheme 1. A Idol condensation of lactone Ilia with aldehydes and a suitable base, such as lithium diisopropyiamide and lithium bis(trimethylsiiyi)azanide, affords compound Illb. The reaction can also be carried out in the presence of Lewis acid additive such as zinc bromide and cerium(III) chloride. Compound Illb can be reduced by a reducing agent, such as diiso butyl, aluminium hydride, followed by further protection of hydroxy! group with a protecting agent, such as acet yl chloride and acet ic

anhydride, to give the key intermediate IIIc. Coupling of compound 11 Ic with compound 11 Id in the presence of an appropriate silyi ether protecting agent, such as N,0- bis(trimethylsilyl)acetamide and hexamethyidisiiazane, and a suitable Lewis acid, such as trimethylsilyl trifluoromethanesulfonate, trimethylsilyl iodide. tin( IV) chloride and titanium tetrachloride, to afford compound H ie. Compound I He is converted to compound 111 f by introduction of 4-methoxytriphenylmethyi protecting group. Deprotection of compound 111 Γ affords compound Illg, followed by mesylat ion with mesylat ing reagent, such as

methanesulfonyl chloride, to give compound I llh, followed by substitution react ion with sodium azide to afford compound IIII. Reduct ion of compound III! gives compound IIIJ with reducing agent, such as Zinc powder in acetic acid. Deprotection of compound l l lj in the presence of an appropriate fluoride reagent, such as t e t ab u t y 1 a m mo n i u m fluoride and ammonium fluoride, affords compound Illk, which can be converted to the final compound H im by deprotection with a suitable acid, such as formic acid.

Scheme 2%

IVc IVd

R^a is R¹ or R .

Compound of interest IVd is prepared according to Scheme 2. Substitution of compound I l lh w ith various amine IVa gives compound IVb. Deprotection of compound IVb in the presence of an appropriate fluoride reagent, such as t et rab u t y 1 a m mo n i u m. fluoride and ammonium fluoride, affords compound IVc. Compound IVc is converted to the final compound IVd by deprotection w ith a suitable acid, such as formic acid.

Scheme 3:

R^b is C ,alkyl.

Compound of interest Vd is prepared according to Scheme 3. Direct reductive animation of amine in compound 111 j with aldehyde Va in the presence of a suitable reducing agent such as aBH(OAc); gives compound Vb. Deprotect ion of compound Vb in the presence of an appropriate fluoride reagent such as tetrabutylammonium fluoride or ammonium fluoride affords compound Vc, w hich is converted to the final compound Y d by deprotection w ith a suitable acid, such as formic acid.

This invention also relates to a process for the preparation of a compound of formula (I) or ( la) comprising the reaction of:

(a) the reaction of a compound of formula ( l l lk),

with an acid;

(b) the react ion of a compound of formula (IV c),

with an acid, wherein R^a is R¹ or R²

(c) the react ion of a compound of formula

with an acid, wherein R^b is Ci <,alkyl; or wherein R^a, R^b, R³, R⁴ are defined above.

In step (a), (b) and (c), the acid can be for example formic acid.

A compound of formula (I) or (la) when manufactured according to the above process is also an object of the invent ion.

PHARMACEUTICAL COMPOSITIONS AND ADMINISTRATION

Another embodiment provides pharmaceutical compositions or medicaments containing the compounds of the invent ion and a therapeutically inert carrier, diluent or exeipient, as well as methods of using the compounds of the invention to prepare such composit ions and medicaments. In one example, compounds of formula (I) or ( la) or their prodrugs may be formulated by mix ing at ambient temperature at the appropriate pH, and at the desired degree of purity, with

physiologically acceptable carriers, i.e., carriers that are non-toxic to recipients at the dosages and concentrations employed into a galenical administration form. The pH of the formulation depends mainly on the particular use and the concentration of compound, but preferably ranges anyw here from about 3 to about 8. In one example, a compound of formula (I) or ( la) or their prodrugs are formulated in an acetate buffer, at pl l 5. In another embodiment, the compounds of formula ( I ) or ( la) or their prodrugs are sterile. The compound may be stored, for example, as a solid or amorphous composit ion, as a lyophilized formulation o as an aqueous solution.

Compositions are formulated, dosed, and administered in a fashion consistent with good medical pract ice. Factors for consideration in this context include the particular disorder being treated, the particular mammal being treated, the clin ical condit ion of the individual pat ient, the cause of the disorder, the site of delivery of the agent, the method of administration, the scheduling of administration, and other factors known to medical practitioners. The "effect ive amount^" of the compound to be admin istered will be governed by such considerations, and is the minimum amount necessary to activate T1.R7 and/or TLR8 receptors and lead to produce type I interferon ( IFN-a and IFN-β) and other pro-inflammatory cytokine genes, which is able to be used be used, but not limited, fo the antiv iral and ant itumor treatment or prevent ion.

In one example, the pharmaceut ical ly effect ive amount of the compound of the invent ion admin istered parenteral ly per dose will be in the range of about 0.1 to 50 mg/kg, alternat ively about 0. 1 to 30 mg kg of pat ient body weight per day, with the typical init ial range of compound used being 0.3 to 1 5 mg/kg/day. In another embodiment, oral unit dosage forms, such as tablets and capsu les, preferably contain from about 20 to about 1000 mg of the compound of the invention.

The compounds of the invention may be administered by any suitable means, including oral, topical ( including buccal and subl ingual ), rectal, vaginal, transdermal, parenteral, subcutaneous, intraperitoneal, intrapulmonary, intradermal, intrathecal and epidural and intranasal, and, if desired for local treatment, intralesional administration. Parenteral infusions include intramuscular, intravenous, intraarterial, intraperitoneal, or subcutaneous administration.

The compounds of the present invent ion may be administered in any convenient administrative form, e.g., tablets, powders, capsules, solutions, dispersions, suspensions, syrups, sprays, suppositories, gels, emulsions, patches, etc. Such compositions may contain components convent ional in pharmaceut ical preparations, e.g., diluents, carriers, pH modifiers, sweeteners, bulking agents, and further active agents.

A typical formulat ion is prepared by mi ing a compound of the present invent ion and a carrier or excipient. Suitable carriers and excipients are well known to those skilled in the art and are described in detail in, e.g., Ansel, Howard C, et al., Ansel's Pharmaceut ical Dosage Forms and Drug Delivery Systems. Philadelphia: Lippincott, Williams & Wilkins. 2004; Gennaro, Alfonso R., et al. Remington: The Science and Practice of Pharmacy. Philadelphia: Lippincott. Will iams & Wilk ins, 2000: and Rowe, Raymond C. Handbook of Pharmaceut ical Excipients. Chicago, Pharmaceutical Press, 2005. The formulations may also include one or more buffers, stabilizing agents, surfactants, wetting agents, lubricat ing agents, emulsifiers, suspending agents, preservatives, ant ioxidants, opaquing agents, glidants, processing aids, colorants, sweeteners, perfuming agents, flavo ing agents, diluents and other known addit ives to provide an elegant presentation of the drug (i.e., a compound of the present invention or pharmaceutical

composit ion thereof) o aid in the manufacturing of the pharmaceut ical product (i.e.,

medicament).

An example of a suitable oral dosage form is a tablet containing about 20 to 1 000 mg of the compound of the invent ion compounded with about 30 to 90 mg anhydrous lactose, about 5 to 40 mg sodium croscarmellose, about 5 to 30 mg polyvinylpyrrolidone ( PVP) K30, and about 1 to 10 mg magnesium stearate. The powdered ingredients are first mixed together and then mixed with a solut ion of the PVP. The result ing composition can be dried, granulated, mixed with the magnesium stearate and compressed to tablet form using convent ional equipment. An example of an aerosol formulat ion can be prepared by dissolving the compound, for example 20 to 1000 mg. of the invention in a suitable buffer solut ion, e.g. a phosphate buffer, adding a tonicifier, e.g. a salt such sodium chloride, if desired. The solut ion may be filtered, e.g., using a 0.2 micron filter, to remove impurit ies and contaminants.

An embodiment, therefore, includes a pharmaceut ical composit ion comprising a compound of formula (I) or (la) o their prodrugs, or pharmaceutically acceptable salts or enant iomers or diastereomers thereof.

In a further embodiment includes a pharmaceut ical composit ion comprising a compound of formula (I) or ( la) or their prodrugs, or pharmaceutically acceptable salts or enant iomers or diastereomers thereof, together with a pharmaceut ically acceptable carrier or excipient.

Another embodiment includes a pharmaceut ical composit ion comprising a compound of formula ( I ) or ( la) or their prodrugs, or pharmaceutically acceptable salts or enantiomers or diastereomers thereof for use in the treatment of cancer or hepat it s B virus infect ion. INDICATIONS AND METHODS OF TREATMENT

The present invention provides methods for treating or preventing cancer, or a hepatitis B viral infection and/or hepatitis C viral infect ion in a patient in need thereof.

The present invent ion further provides methods for introducing a therapeutically effective amount of a formula (I) or ( la) compounds or their prodrugs, or other compounds of the invention into the blood stream of a patient in the treatment and/or prevention of cancer, or hepatitis B and/or C viral infect ion.

The methods of the present inv ent ion are particularly well suited for human patients. In particular, the methods and doses of the present invention can be useful for, but not limited to, cancer, I IBV and/or HCV infected patients. The methods and doses of the present invent ion are also useful for pat ient s undergoing other ant iviral treat ments. The prevention methods of the present inv ent ion are particularly useful for patients at risk of v iral infect ion. These pat ients include, but are not limited to health care workers, e.g. , doctors, nurses, hospice care givers;

military personnel: teachers; childcare workers; patients traveling to, or living in, foreign locales. in particular third world locales including social aid workers, missionaries, and foreign diplomats. Finally, the methods and compositions include the treatment of refractory patients or patients resistant to treatment such as resistance to reverse transcriptase inhibitors, protease inhibitors, etc.

Another embodiment includes a method of treating or prev enting cancer, or hepatitis B viral infection and/or hepat itis C v iral infect ion in a mammal in need of such treatment, wherein the method comprises administering to said mammal a therapeutically effective amount of a compound of formula (I) or ( la) or their prodrugs, or enantiomers, diastereomers, prodrugs or pharmaceutically acceptable salts thereof.

EXAMPLES

The invent ion will be more fully understood by reference to the following examples. They should not, however, be construed as limit ing the scope of the inv ention.

ABBREVIATIONS

ACN: acetonitrile

BSA: N, ( -bis(trimethylsiiyi)acetamide

DIBAL-H: diiso butyl aluminium hydride DMAP: 4-dimcthylaminopyridinc

DCM: dichloromcthane

EC50: the molar concentration of an agonist, which produces 50% of the ma imum

possible response for that agonist.

EtOAc: ethyl acetate

FBS: fetal bovine serum

11 PLC: high performance liquid chromatography

LDA: lithium diisopropylamide

MMTrCi: 4-methoxytriphenylmethyl chloride

MS (ESI): mass spectroscopy (electron spray ionization)

obsd. : observed

SFC: supercritical fluid chromatography

TBAF: tetrabutylammonium fluoride

IMF: tetrahydrofuran

TBDPSCi: teri-butylchiorodiphenylsilane

TMSOTf: trimethylsilyi trifluoromethanesulfonate

v/v: volume ratio

GENERAL EXPERIMENTAL CONDITIONS

Intermediates and final compounds were purified by flash chromatography using one of the following instruments: i) Biotage SPl system and the Quad 12/25 Cartridge module, ii) ISCO combi-flash chromatography instrument. Silica gel Brand and pore size: i) KP-SIL 60 A, particle size: 40-60 μιη; ii) CAS registry NO: Silica Gel: 63231 -67-4, particle size: 47-60 micron silica gel; iii) ZCX from Qingdao Haiyang Chemical Co.. Ltd, pore: 200-300 or 300-400.

Intermediates and final compounds were purified by preparative I I PLC on reversed phase column using X Bridge™ Perp Ci₈ (5 iim, OBD™ 30 x 100 mm) column or SunFire™ Perp d₈ (5 inn, OBD™ 30 100 mm) column.

Chirai Separation was conducted on Thar 350 preparative SFC using ChiralPak AD- l Oii (200 x 50 mm I .D. ) with mobile phase A for CO_? and B for ethanoi.LC/MS spectra were obtained using a Waters UPLC-SQD Mass. Standard LC/MS conditions were as follows

(running time: 3 minutes): Acidic condition: A: 0.1% formic acid and 1% accto nit rile in H₂0; B: 0.1% formic acid in acetonitrile;

Basic condit ion: A: 0.05% ΝΗ₃Ή₂0 in H₂0; B: acetonitrile.

Mass spectra (MS): generally only ions which indicate the parent mass are reported, and unless otherwise stated the mass ion quoted is the positive mass ion ( Μ +Ή ) .

NMR Spectra were obtained using Bruker Avancc 400MHz.

Al l reactions involving air-sensit ive reagents w ere performed under an argon atmosphere. Reagents were used as received from commercial suppliers without further purificat ion unless otherwise noted.

PREPARATIVE EXAMPLES

Example 1

5-Amrao-3-[(2i?,3S,5S)-3-[(lS)-l-amraoethy^^

y!|-6//-thiazolo|4,5-</| pyrimidine-2,7-dione ( Example 1 -A) and 5-amieo-3-[(2J?,3S,5S)-3- [(li?)-l-amieoethy!]-5-[(lS)-l-hydroxypropy!]tetrahydrofurae-2-yl]-6H-thlazolo[4,5- d\ pyrimidine-2,7-dione (Example 1-B)

1 -A 1 -B

Preparation of (2S)-5-oxolelrahydrofuran-2-earbox lic acid

1 a

(2S)-2-Aminopentanedioie acid (2.50 kg, 16.99 mol) was dissolved in H₂0 (6 L) and concentrated HQ (3.5 L), then a solution of NaN0₂ ( 1 .76 kg, 25.49 mol) in H₂0 (5 L) was addcd to previous solution slowly at -5 °C to 0 °C. After addition, the reaction mixture was stirred at 28 °C for 1 6 hours, then the reaction mixture was concentrated below 50 °C to give a residue, which was suspended in ethyl acetate (5 L). After filtrat ion , the filtrate was dried over anhydrous Na₂S0₄ and concentrated in vacuo to give 1 .5 kg of ( 2S)-5 -oxot et rah yd ro fu ra n-2- carboxylic acid as a colorless oil which was used in the next step without further purificat ion.

Preparation of (2S)-5-oxoletrahydrofuran-2-carbonyl chloride

1 b

To a mixture of (25)-5-oxotetrahydrofuran-2-carboxylic acid ( 1 .00 kg, 7.69 mol ) in DCM ( 10.0 L) and DMF ( 1 0.0 ml.) was added (COCl)₂ (2.93 kg, 23.06 mol) dropwise and slowly at 0 °C under N₂. The reaction was stirred at 0 °C for 30 minutes, then heated to 25 °C and st irred for further 2 hours. After the reaction was completed, the reaction mixture was concentrated in vacuo at 40 °C to afford 1 .0 kg of (25)-5-oxotetrahydrofuran-2-carbonyi chloride as a yellow oil, which was used in the next step without further purification.

Preparation of (5S)-5-propanoyltetrahydrofuran-2-one

1 c

To a solution of (25)-5-oxotetrahydrofuran-2-carbonyl chloride ( 1 .00 kg, 6.73 mol) in THF (5.0 L) was added bra mo( et h y l ) magnes i u m ( 2.24 L, 6.73 mol) dropwise at -78 °C under N₂. After the addition, the reaction mixture was stirred at -78 °C for 3 hours. Then the react ion mixture was poured into saturated NH₄C1 solution ( 100 ml . ), then extracted with ethyl acetate, dried over anhydrous Na₂S0₄, filtered and concentrated in vacuo. The residue was purified by column chromatography (eluting with 10-50% ethyl acetate in petroleum ether) to give 500 g of (55)-5-propanoyitetrahydrofuran-2-one as a light yellow oil.

Preparation of (5S)-5-|( lS)- l-hydroxyprop |tetrahydrofuran-2-one

id To a solution of (55)-5-propanoyltetrahydrofuran-2-one ( 1 .50 kg, 1 0.55 mol ) in THF ( 1 5.0 L) was added K-selectride (2.34 kg, 1 0.55 mol ) dropwise at -78 °C under N₂. The reaction mixture was stirred at -78 °C for 3 hours. The resulting mixture was poured into a cold aqueous aHCC solut ion ( 1 5 L) and stirred for 1 2 hours. The aqueous phase was extracted with ethyl acetate ( 10 1.) four times. The combined organic phase was washed with brine (5 L), dried with anhydrous a.>SO.i, filtered and concentrated in vacuo. The residue was purified by column chromatography (elut ing with 0-30% ethyl acetate in petroleum ether) to afford 500 g of (55)-5- [( 1 S)- 1 -hydroxy-propyl ]tetrahydrofuran-2-one as a yellow oil. (Refer to Eur. J. Med. Chem. 1997, 32, 61 7-623. ) Preparation of (5S)-5-[(lS)-l-[tert-bi!tyl(dipheiiyl)sllyl]oxypropyl]tetrahydrofiirae-2-o!ie

TB

1e

To a mixture of (5S)-5-[( 1 S)- 1 -hydroxypropyl]tetrahydrofuran-2-onc (500 g, 3.5 mol) and imidazole (708 g, 10.4 mol ) in DMF (8.0 L) was added TBDPSCI ( 1 .43 kg, 5.2 mol ) dropwise at 0 °C under N₂. After being st irred at 25 °C for 1 2 hours, the reaction mixture was diluted with water ( 120 ml. ) and extracted with ethyl acetate (50 ml. ) three times. The combined organic phase was washed with brine (30 ml . ), dried over anhydrous Na₂S0₄, filtered and concentrated in vacuo. The residue was purified by column chromatography (elut ing with 30-50% ethyl acetate in petroleum ether) to afford 860 g of (5S)-5-[(lS)-l-[tert- butyl(diphenyl )silyl]oxypropyl]tetrahydrofuran-2-one as a white solid.

C ompound l e: Ή NMR (400 MHz, CDC1₃) d^"ppm: 0.76 (t, J= 7.47 Hz, 31 1 ), 1.08 (s, 9 H),

1 .36- 1 .52 (m, 1H), 1 .61 - 1 .75 (m, 1H), 2.06-2.24 (m, 21 1 ), 2.4 1 -2.67 (m, 2H), 3.61 -3.74 (m, 1H), 4.56 (td, J= 7.09, 3.64 Hz, IH), 7.3 1 -7.57 (m, 61 1 ), 7.61 -7.82 (m, 4H).

1f-A 1f-B

To a .solution of (5S)-5-|( 1 S)- 1 -[/w-butyl(diphenyl )silyl ]oxypropyl]tetrahydrofuran-2-one (200 g, 520 mmol) in THF (500 ml.) was added I D A (390 ml..780 mmol) slowly at -78 °C and stirred under N₂ for further 2 hours. To the above mixture was added CH₃CHO (34.4 g, 780 mmol) slowly at -78 °C and stirred for another 1 hour. The reaction was quenched with NH₄CI solution (2 L), diluted with ethyl acetate (2 L), the organic phase was washed with brine (11. ) and dried over anhydrous Na₂S0₄, filtered and concentrated in vacuo to give the residue which was purified by column chromatography (eluting with 0-10% ethyl acetate in petroleum ether) twice to give 42 g of (3S,5S)-5-[( 15)- 1 -[ w/-butyl(diphenyl )sily ]o.xypropyl]-3-[( 1 /?)- 1 - hydroxyethyl]tetrahydrofuran-2-one (Compound lf-A) and 46 g of (3S,5<S)-5-[(l<S)-l-[terf- butyl(diphenyl)silyl]o.xypropyl] -3 - [( 15)- 1 -hydro.xyethyljtetrahydro furan-2-one (Compound 1 f- B).

The stereochemistry on five member ring has been established by 2D NMR NOESY experiments. For Compound lf-A and Compound lf-B, correlation of C l and C⁵H was not observed.

TB

1f-A 1f-B

Compound lf-A: Ή NMR (400 MHz, CDCI₃) δ ppm: 0.72 (t, J= 7.53 Hz, 3H), 1.07 (s, 9H), 1.23 (d,J= 6.40 Hz, 3H), 1.36-1.51 (m, 1H), 1.65-1.80 (m, 111), 2.10-2.24 (m, 1H), 2.35 (dt,J = 12.83, 9.08 Hz, 1H), 2.86 (ddd, J= 10.29, 9.03, 3.14 Hz, 1H), 3.66 (ddd, J= 8.28, 5.08, 2.95 Hz, 1H), 4.35 (dd,J= 6.40.3.01 Hz, 1H), 4.58 (dt,J= 9.13.3.15 Hz, 1H), 7.34-7.54 (m, 611), 7.63-

7.81 (m,4H).

Compound lf-B: Ή NMR (400 MHz, CDCI3) δ ppm: 0.72 (t, J= 7.47 Hz, 3H), 1.08 (s, 9H), 1.23 (d, J= 6.27 Hz, 3H), 1.38-1.53 (m, 1H), 1.66-1.81 (m, 1H), 1.97 (dt, J= 13.05, 9.60 Hz, 1H), 2.24 (ddd,J= 12.92, 10.16, 2.51 Hz, 1H), 2.68-2.85 (m, 1H), 3.65 (ddd,J= 8.34, 5.08, 2.89 Hz, 1H), 3.79-3.95 (m, 1H), 4.56 (dt, J= 9.29, 2.64 Hz, 1H), 7.38-7.54 (m, 6H), 7.70 (ddd, J = 10.57, 8.00, 1.51 Hz, 411).

(Compound lp-B)

TB

1 p-A 1 p-B

To a solution of (35,55)-5-[(15)-l-[tert-butyl(diphenyl)silyl]oxypropyl]-3-[(li?)-l- hydro xyethyl]tetrahydrofuran-2-one (Compound If- A, 20 mg, 0.047 mmol), DMAP (0.6 mg, 0.005 mmol) and Et₃N (9.5 mg, 0.094 mmol) in DCM (2 ml.) was added (2i?)-3,3,3-trifluoro-2- methoxy-2-phenyl-propanoyl cliloride (24 mg, 0.094 mmol) slowly at 0 °C and stirred at 25-28 °C under N₂ for 12 hours. The reaction mixture was quenched with water (3 ml,), extracted with DCM (2 ml.) twice and dried over anhydrous Na₂S0₄. After concentrated in vacuo, the residue was purified by preparative TLC (eluting with 1 :8 ethyl acetate in petroleum ether) to give 10 mgof [(lR)-l-[(3S,5S)-5-[(lSH-[tert-b^^

yljethyl] (25)-3.3.3-trifiuoro-2-mctho.xy-2-phenyl-propanoate (Compound lp-A).

In analogy to Compound lp-A, [ ( 1 /?)- 1 -[(3S.5S)-5-[( 1 S)- 1 -[m- butyl(diphenyl)silyl]oxypropyl]-2-oxo-tetrahydrofuran-3-yl]ethyl] (2i?)-3,3,3-trifluoro-2- metho.xy-2-phenyl-propanoate (Compound lp-B) was prepared by using ( 5)-3 ,3.3-t ri fi uoro-2- metho.xy-2-phcnyl-propanoyl chloride instead of (2i?)-3,3,3-trifluoro-2-methoxy-2-phenyl- propanoyl chloride.

Compound lp-A: Ή NMR (400 MHz, CDCh) δ ppm: 0.68 (t, J= 7.47 Hz, 3H), 1.05 (s, 911), 1.33-1.41 (m.111), 1.43 (d, J= 6.40 Hz, 311).1.63-1.75 (m, HI), 2.15-2.24 (m, 211), 2.97 (td, J = 9.63, 3.83 Hz, 111).3.50-3.55 (m, 311), 3.58-3.64 (m, HI), 4.37-4.45 (m, 111).5.54-5.63 (m, 1 H), 7.37-7.48 (m, 911), 7.48-7.54 (m, 2H), 7.63-7.72 (m, 4H). Compound lp-B: Ή NMR (400 MHz, CDC1₃) δ ppm: 0.66 (t, J= 7.40 Hz.3H), 1.05 (s, 9H), 1.34 (d, J= 6.27 Hz, 3H), 1.37-1.49 (m, IH), 1.64-1.75 (m, 111).2.13-2.21 (m, 2H), 2.96 (td, J = 9.41, 2.64 Hz, IH), 3.51 (s, 3H), 3.57-3.64 (m, HI), 4.38-4.49 (m. HI), 5.50-5.61 (m, IH), 7.36- 7.51 (m, 1 HI), 7.68 (t, J= 8.47 Hz, 4H). According to the Mosher's model (Chem. Rev.2004, 104, 17-117.) and Ή NMR results, the absolute configurations of Compound lp-A and Compound lp-B are shown as above listed. Therefore, the absolute configurations of Compound lf-A and Compound lf-Β are shown as above.

I (3S,5S)-3- 1 ( IS)- 1 -acetoxy ethy 11 -5- 1 ( 1 S)- 1 - |ft'rr- butyl(diphenyl)sil |oxypropyl|tetrahydrofuran-2-yl| acetate (Compound lh-B)

TB

To a solution of (35,55)-5-[( 15)- 1 -[/m-butyl(diphenyl )silyl]oxypropyl ]-3-[( 1 /?)- 1 - hydro yethyl]tetrahydrofuran-2-one (Compound lf-A, 17 g, 40 mmol) in toluene (200 ml.) was added DIBAL-H ( 1 M, 120 ml., 120 mmol) dropwise at -78 °C, and the reaction mixture was stirred at -78 °C under N₂ for 1 hour. The reaction was quenched with saturated NH₄C1 solution and extracted with ethyl acetate. The organic pha.se was extracted and washed with brine, dried and concentrated to give the crude product, which was re-dissolved in pyridine (100 ml.) followed by addition of DMAP (500 mg, 4 mmol) and Ac₂0 (30 g, 300 mmol) at 0 °C. After being stirred at 25 °C for 16 hours, the reaction was quenched with saturated allCO; solution and extracted with ethyl acetate. The organic pha.se was extracted and washed with brine, dried and concentrated to give the crude product, which was purified by column chromatography (during with 0-10% ethyl acetate in petroleum ether) to give 13 g of [(3£,5<S)-3-[(lR)-l- acetoxyethyl]-5-[( 15)-l-[/t -butyl(diphenyl)silyl]oxypropyl]tetrahydrofuran-2-yl] acetate (Compound lh-A) as a colorless oil.

In analogy to Compound lh-A, [ (35.55)-3-[( 15)- 1 -acetoxyethyl ]-5-|( 15)- 1 -|>C - butyl(diphenyl)siIyl]oxypropyi]tetrahydrofuran-2-yl] acetate (Compound 1 h-B) was prepared by using (35,55)-5-[(15)-l-[tert-butyl(diphenyl)silyl]oxypropyl]-3-[(15)-l- hydroxyethyi]tetrahydrofuran-2-one (Compound lf-B) instead of Compound If- A.

(Compound li-A) and |(LS l-|(2 ?,35,5S)-2-(5-amino-2,7-dioxo-6//-thiaz()lo|4,5- </| pyrimidin-3-yl)-5-|(lA l-|fc'^butyl(diphe^

acetate (Compound li-B)

1i-A 1i-B

To a suspension of 5-armno-3,6-dihydrothiazolo[4,5-<i]pyrimidine-2,7-dione (3.6 g, 20 mmol) in MeCN ( 100 mL) was added BSA ( 16 g, 80 mmol) at 25 °C, and the reaction mixture was heated to 85 °C for 1 hour until a clear solution was formed. After the mixture was cooled to 0 °C, [(3S,5S)-3-[( l/ -l -acetoxyethyl ]-5-[( 1 S)- 1 -[t rt- butyl(diphenyl)silyl]oxypropyl]tetrabydrofiiran-2-yl] acetate (Compound 1 h- A, 5.2 g, 10 mmol) was added followed by addition of TMSOTf (4.4 g, 20 mmol). After being stirred at 25 °C for 16 hours, the reaction was quenched with saturated al ICO; solution and extracted with ethyl acetate. The organic phase was extracted and washed with brine, dried and concentrated in vacuo to give the crude product, which was purified by column chromatography (e!uting with 0-2% methanol inDCM) to give 6 g of [( 1 /?)- 1 -[(2/?.3S.55)-2-(5-amino-2.7-dioxo-6//-ttiiazolo[4.5- i/]pynmidin-3-yl)-5-[( 1 S)- 1 - [tert-butyl(diphenyl)silyi]oxypropyl]tetrahydro furan-3-ylj ethyl] acetate (Compound II- A) as a yellow foam.

In analogy to Compound li-A, [( 15)- 1 -[(2/?.3.S^".5S)-2-(5-amino-2.7-dioxo-6//- thiazo lo [4,5 - </] p y r i m i d i n - 3 - y 1 ) - 5 - [ ( 1 S)- 1 - [ t ri-b u t y I ( d i p li e n y 1 ) s i I y I J o x y p ro py!jtet ra h yd o fu a n - 3 - yljethyl] acetate (Compound li-B) was prepared by using [ (3S,55)-3-[( 1 $)- 1 -acetoxyethyl ]-5- [( 15)-l-[/e )utyl(diphenyl)silyl]oxypropy ]tetrahydrofuran-2-yl] acetate (Compound Ih-B) instead of Compound lh-A. Preparation of [(lR)-l-[(2i?,3S,5S)-5-[(lS)-l-[tei -biity!(dipheny!)siIy!]oxypropy!]-2-[5-[[(4- methoxyphenyl)-diphenyl-methyl| amino] -2,7-dioxo-6//-thiazolo [4,5-ffl pynmidin-3- yl|tetrahydrofuran-3-yl|ethyl| acetate (Compound lj-A) and | ( 15)- 1 - 1 (2RJS,5S)-5- \( \S)-l - [tert-bntyl(dlphenyl)si!yl] oxy ropyl] -2- [5- | |(4-methoxyphenyl)-diphenyl-methyl| amino] - 2,7-dioxo-6//-thiazoio|4,5-</| pyrimidin-3-yl|tetrahydrofuran-3-yl|ethyl| acetate (Compound lj-B)

1j-A 1j-B

To a solution of [( \ R)- \ -[(2/i,35,55)-2-(5-amino-2,7-dioxo-6/7-thiazolo[4,5-J]pyrimidiii-3- yl)-5 - [( 15)- 1 - [ter/-butyl(diphenyl)silyl]oxypropyl] tetrahydrofliran-3 -yl] ethyl] acetate

(Compound li-A, 3.7 g, 5.8 mmol ) in DCM ( 1 00 ml.) was added collidine (2.1 g, 1 7.4 mmol), AgNC (2.9 g, 1 7.4 mmol) and MMTrCl (5.4 g, 1 7.4 mmol) at 0 °C, and the reaction mixture was stirred at 20 °C for 2 hours. Then the reaction was quenched with water (80 ml. ), and the reaction mixture was filtered and extracted with ethyl acetate ( 100 ml.) three times. The combined organic layer was dried over anhydrous Na^SO i, filtered, concentrated, and the residue was purified by column chromatography (elut ing with 1-5% methanol in DCM) to give 5.0 g of [( 1 R)- 1 -[(2/?,35,55)-5-[ ( 1 S)- 1 -[r_t'/7-butyl(diphenyl )silyl !oxypropyl ]-2-[ 5-[ [(4-methoxypheiiyl )- diphenyl-methyl ]amino]-2,7-dioxo-6//-thiazolo[4,5-J]pyrimidin-3-yl]tctra

acetate (Compound lj-A) as a yellow solid. MS obsd. ( ESI ) [( M+H ) ] : 909.3.

In analogy to Compound lj-A, [( 1 S)- 1 -[(2tf,3S,5S)-5-[( 1 S)- 1 -[t rr- butyi(diphenyl)siiyl]oxypropyl]-2-[5-[[(4-methoxyphenyl)-diphenyl-methyi]amino]-2,7-dioxo- 6/7-thiazolo[4,5-J]pyrimidin-3-yl ]tetrahydrofuran-3-yl ]cthyl ] acetate (Compound lj-B) was prepared by using [ ( 15)- 1 -[(2/ ,35,55)-2-( 5-amino-2 J-dio o-6//-thiazolo[4,5-J]pyrimidin-3-yl )- 5-[ ( 15)- 1 - [tert-butyl(diphenyi)siiyl]oxypropyl]tetraliydrofuran-3 -yl] ethyl ] acetate (Compound l i-B) instead of Compound li-A. Preparation of 3-[(2«,3S,5S)-5-[(lS)-l-[ter/-butyl(diphenyl)silyl]oxypropyl]-3-[(l_JR)-l- hydroxyethyl]tetrahydrofuran-2-yl]-5-[[(4-methoxyphenyl)-diplienyl-methyl]amino]-6H- thiazolo|4,5-</| pyrimidine-2,7-dione (Compound I k- A ) and 3- 1 ( 2 Λ,35,5Λ")-5- 1( 15)-1-| tert- butyl(diphenyl)silyl| oxy ropyl] -3- [(IS)- 1-hydroxy ethyl] tetrahydrofuran-2-yl| -5- [ |(4- methoxyphenyl)-diphenyl-methyl| amino] -6//-thiazolo |4,5-</| pyrimidine-2,7-dione

(Compound I k-B)

1 k-A 1 k-B To a solution of [( \ R)- \ -| (2tf,3S,5S)-5-[( 1 S)- 1 -|>_t-r/-butylidiphcnyl )silyl ]oxypropyl]-2-[5-

[[(4-methoxyphenyi)-diphenyl-methyl]am

y i ] t e t ra h yd ro furan-3-yl ] c t h y l ] acetate (Compound lj-A, 5.0 g, 5.5 mmol) in methanol (60.0 niL) was added ₂CO₃ (4.5 g, 33.0 mmol). The mixture was stirred at 25 °C for 1 2 hours. The solid was removed by filtration and the filtrate was concentrated in vacuo. Then the residue was purified by column chromatography (eluting with 2-5% methanol in DCM) to give 3.8 g of 3- [(2/?,3S,5S)-5-[( 15)- 1 -[/c/7-butyl(diphcnyl )silyl joxypropyl j-3-[ ( \ R)- \ - hydroxyethy ]tetrahydrofuran-2-yl ]-5-[ [(4-metlK)xyphcnyl )-diphenyl-methyl]

thiazolo(4,5-(/|pyrimidine-2.7-dione (Compound 1 k- A ) as a white solid.

In analogy to Compound lk-A, 3-[(2/?,35,55)-5-[ ( 15)- 1

buty](diphenyl )silyl joxypropyl ] -3-[ ( 15)- 1 - h yd ro x y e t h y I ] t e t ra h yd ro furan-2-yl] -5 - [ [(4- methoxyphenyl)-diphenyi-methyi]amino]-6H-thiazoio[4,5-</]pyrimidine (Compound l k-B) was prepared by using [(15)-l-[(2i?,35,55)-5-[(15)-l-[tert- butyl(diphenyi)silyl]oxypropyl]-2-[5-[[(4-methoxyphenyl)-diphenyl-methyl]amino]-2,7-dioxo- 6//-thiazolo[4,5-J]pyrimidin-3-yl]tetrahydrofuran-3-yl]ethyl] acetate (Compound Ij-B) instead of Compound lj-A.

Preparation of [(l«)-l-[(2«,3S,5S)-5-[(lS}-l-[te^butyl(diphenyl)silyl]oxypropyl]-2-[5-[[(4- metlioxyphenyl)-diphenyl-metliyl| amino] -2,7-dioxo-6//-thiazolo [4,5-rf] pyrimidin-3- y 1| tet rahyd rofu ran-3- 11 ethy 11 methanesulfonate (Compound 1 l-A) and [(lS)-l-[(2i?,3S,5S)- 5-[(lS)-l-[teri-b tyl(diphenyl)silyl]oxypropyl]-2-[5-[[(4-methoxyphenyl)-dlphenyl- methyl] amino] -2,7-dioxo-6//-thiazoIo |4,5-i/|pyrimidin-3-yl| tetrahydrofuran-3-yl| ethyl] methanesulfonate (Compound l l-B)

11-A 1 S-B

To a .solution of 3-[(2R,35,5S)-5-[(lS) -[tert-butyl(diphenyl)sUyl]oxypropyl]-3-[(lS)-l- h yd ro x y et h y i] t et rah yd ro fu ra n - 2 - y I ] - 5 - [ [(4-mcthoxyphenyl )-diphenyl-methyl] amino] -6H- thiazolo[4,5-J]pyrimidine-2,7-dione (Compound lk-B, 2.5 g, 2.88 mmol) in pyridine (20.0 mL) was added methanesulfonyl chloride (495.4 mg, 4.32 mmol ) dropwise at 0 °C and the reaction mixture was stirred at 25 °C under N₂ for 12 hours. The reaction was quenched with aqueous NaHCOs (50 ml . ), extracted with ethyl acetate (50 mL) tw ice, the combined organic layer was dried over anhydrous a^SO.). After filtration, the solvent was removed in vacuo to give 2.5 g of the crude [( 1 S)- 1 -[(2/?.3S.5S^")-5-[( 1 S)- 1 -[/ /Y-butyl(diphenyl)silyl ]oxypropyl]-2-| 5-[[(4- methoxyphcnyl )-diphenyl-methyl]amino]-2,7-dioxo-6//-thiazolo[4,5

yl jtetrahydro furan-3-yl jethyl] methanesiil fonate (Compound l l-B) as a brown oil, which was used in the next step directly w ithout further purification.

In analogy to Compound ll-B, [( l / - l - j(2tf .3S,5S)-5-[( 1 S)- 1 -[t rt- butyl(diphenyi)siiyi]oxypropyi]-2-[5-[[(4-methoxyphenyi)-diphenyl-methyl]amino]-2,7-dra 6//-thiazolo[4,5-J]pyrimidin-3-yl]tetrahydrofuran-3-yl]ethyl j methanesiil fonate (Compound 11- A) was prepared by using 3-[(2 ?,35.55)-5-[( 1 S)- 1 -[ /t'/-/-butyl(diphenyl )silyl]oxypropyl j-3-[ ( 1 /?)- 1 -hydroxyethyl jtetrahydro furan-2-yl]-5- [ [(4-methoxyphenyl )-diphenyl-methyl j amino] -6H- thiazolo[4.5-(/]pyrimidine-2.7-dione (Compound I k- A) instead of Compound l k-B.

Preparation of 3-[(2it,35,55)-3-[(15)-l-azidoethyl]-5-[(15 l-[teif- butyl(dlphenyl)sllyl]oxypropyl]tetrahydrofuran-2-yl]-5-[[(4-methoxyplienyl)-diphenyl- methylj aminoj -6//-thiazolo|4,5-</| pyrimidine-2,7-dione (Compound 1 m- A) and 3- |(2 f,35,5S)-3- |( l ?)-l-azidoe(hyl| -5- [(15)-l-[te t- butyl(dlphenyl)sllyl]oxypropyl]tetrahydrofuran-2-yl]-5-[[(4-methoxyphenyl)-dlphenyl- methyl] mino] -6//-thiazoIo |4,5-</| pyrimidinc-2,7-dionc (Compound 1 m-B)

1 m-A 1 m-B

To a solution of [( 15)- 1 -[ (2/?.3S.5S)-5-[ ( I S)- 1 -[ /e^</Y-buty](diphenyl )silyl]oxypropyl]-2-[5- [[(4-mcthoxyphcnyl)-diphenyl-methyl]amino ]-2,7-dioxo-6//-thiazolo[4,5-J]py

yi]tetrahydrofuran-3-yi] ethyl] methanesulfonate (Compound ll-B, 1 .3 g, 1.38 mmo! ) in N,N- d imethylformam ide ( 1 0.0 ml. ) was added sodium azide (268.2 mg, 4. 13 mmol ) slowly at 25 °C and the reaction mixture was stirred at 60 - 80 °C under N₂ fo 12 hours. The reaction solution was cooled to 25 °C and poured into water (50.0 ml. ), extracted with ethyl acetate (30 ml. ) twice. The combined organic layer was dried over anhydrous NajSO). After filtration, the solvent was removed in vacuo and the residue was purified by column chromatography (during with 0-2% methanol in DCM) to give 0.75 g of 3-[(2i?,35,55)-3-[(li?)-l-azidoethyl]-5-[(15)-l-[tert- butyl(diphenyl)silyl]oxypropyl]tetrahydrofuran-2-yl]-5-[[(4-methoxyphenyl)-diphenyl- methyi]amino ]-6//-thiazolo[4,5-J]pyrimidine-2,7-dione (Compound 1 m-B) as a brown solid.

In analogy to Compound l m-B. S- i^^S^-S-Kl^-l-azidoethyy-S-iil^-l-tteri- butyl(diphenyl)silyi]oxypropyi]tetrahydrofuran-2-yi]-5-[[(4-methoxyphenyi)-diphenyi- methyl ]amino j-6/7-thiazolo[4,5-i/]pyrimidine-2,7-dione (Compound 1 m-A) was prepared by using [(li?)-l-[(2i?,35^*,5₁S)-5-[(15)-l-[tert-butyi(diphenyl)siiyl]oxypropyl]-2-[5-[[(4- methoxyphenyi)-diphenyl-methyl]amino]-2,7-dioxo-6H-thiazoio[4,5-ii]pyrimidin-3- y I ] t e t ra h yd ro fu ra n - 3 - y I ] e t h y 1 j methanesulfonate (Compound 1 l-A) instead of Compound l l-B.

1n-A 1n-B

To a solution of 3-[(2/?.3S.5S)-3-[( l /?)- ! -azidocthyl]-5-[( 1 $)- 1 -[tert- butyl(diphenyl)silyl]oxypropyl]tetrahydrofuran-2-yl]-5-[[(4-methoxyphenyl)-dipheny

methy]]amino]-6//-thiazolo|4.5-(/]pyrimidinc-2.7-dione (Compound lm-B, 2.1 g, 2.35 mmol) in tetrahydroiuran (20.0 ml.) was added Zn (307.8 mg, 4.7 mmol) and acet ic acid (282.7 mg.4.7 mmol), then the reaction mixture was stirred at 25 °C for 12 hours. The reaction was quenched with saturate NaHCOs (10 mL) solution and extracted with ethyl acetate (30 mL) twice. The organic layer was dried over anhydrous Na₂S0₄ and concentrated in vacuo. The residue was purified by column chromatography (eluting with 0-2% methanol in DCM) to give 1.4 g of 3- [(2/?,3S,5S)-3-[(l/?)- 1 -aminoethyl] -5-[(15)-l -[teri- butyi(diphenyi)silyl]oxypropyi]tetrahydrofuran-2-yl]-5-[[(4-methoxyphenyi)-diphenyi- methyl]amino)-6//-thiazolo[4,5-J]pyrimidiiie-2,7-dione (Compound In-B) as a yellow solid.

In analogy to Compound ln-B, 3-[(2i?,3S,5.5)-3-[(1.5)-l-aminoethyi]-5-[(15)-l-[tert- butyl(diphenyi)silyl]oxypropyl]tetrahydrofuran-2-yl]-5-[[(4-methoxyphenyl)-diphenyi- methyl ]amino j-6//-thiazolo[4,5-(/]pyrim id ine-2,7-dione (Compound ln-A) was prepared by using 3-[(2i?,35,55)-3-[(15)-l-azidoethyi]-5-[(15)-l-[teri- butyi(diphenyl)siiyl]oxypropyl]tetrahydrofuran-2-yi]-5-[[(4-methoxyphenyl)-diphenyl- methyl]aminoJ-6//-thiazolo[4.5-(/jpyrimidine-2,7-dione (Compound lm-Α) instead of

10-A 10-B

A solution of 3-[(2R,3S,5iS)-3-[(lR)-l-aminoethyl]-5-[(lS)-l-[tert- butyl(diphenyl)silyl]oxypropyl]tetrahydrofuran-2-yl] -5 - [[(4-metho.\yphcnyl)-diphenyl- met yl jamino]-6//-ttuazolo[4.5-J]pyrimidinc-2,7-dione (Compound In-B, 0.32 g, 0.36 mmol) in t ct rabu tyla m mo n i 11 m fluoride (3M in THF, 10.0 mL) was stirred at 50 °C for 12 hours. The reaction solution was diluted with water (20 mL), extracted with ethyl acetate (20 ml.) twice. The combined organic layer was dried over anhydrous Na₂S0₄, filtered and concentrated in vacuo. The residue was purified by column chromatography (eluting with 10-30% ethyl acetate in petroleum ether) to give 0.21 g of 3-[(2/?,3.S^",5S)-3-[( \R)-\ -aminoethyl ]-5-[( 1 S)- 1 - hydro xypropyl]tetrahydrofuran-2-yl]-5-[[(4-methoxyphenyi)-diphenyi-methyl]amino]-6H- thiazolo[4,5-(/]pyrimidine-2,7-dione (Compound 1 o-B) as a yellow solid.

In analogy to Compound lo-B, 3-[(2/?,35,5.S^")-3-[( 1 S)- 1 -aminoethyl j-5-[( 1 S)- 1 - hydro xypropyi]tetrahydrofuran-2-yi]-5-[[(4-methoxyphenyl)-diphenyl-methyi]amino]-6H- thiazolo[4,5-(/]pyrimidine-2,7-dione (Compound 10- A ) was prepared by using 3-[(2/?,35,5S)-3- |(15)-1 -aminoethyl] -5 - [( 15)- 1 - [tert-butyl(diphenyl)silyl]oxypropyi]tetrahydro furan-2-yi] -5 - [ [(4- methoxyphenyi)-diphenyi-methyl]amino]-6H-thiazolo[4,5-i]pyrimidine-2,7-dione (Compound 1 n- A ) instead of Compound In-B.

B)

1-A 1-B

A solution of 3-[(2/?,3S,5S)-3-[( I R)- 1 -aminoethyl ]-5-[( l S)- 1 - hydro xypropyl]tetrahydrofuran-2-yl]-5-[[(4-meth^

thiazolo[4,5-J]pyrinudine-2,7-dionc (Compound lo-B, 200.0 mg, 0.49 mmol) in formic acid (5.0 ml.) was stirred at 20-25 °C under N₂ for 0.5 hour. The mixture was concentrated in vacuo and the residue was purified by preparative HPLC and SFC to give 23.0 mg of 5-amino-3- [(2/?,3S,5S)-3-[( I /?)- I -aminoethyl ]-5-[( I S)- 1 -hydro.xypropyl]tetrahydrofuran-2-yl]-6//- thiazo]o[4,5-(/jpyrimidine-2,7-dione (Example 1-B) as a light yellow solid.

In analogy to Example 1-B, 5-amino-3-[(2/?,3S,55)-3-[( 1 S)- 1 -aminoethyl ]-5-[( 1 S)- 1 - hydroxypropyi]tetrahydrofiiran-2-yl]-6H-thiazolo[4,5-d]pyrimidine-2,7-dione (Example 1-A) was prepared by using 3-[(2/?,3S,5S)-3-[( 1 S)- 1 -aminoethyl ]-5-[ ( 15)- 1 - hydro xypropyi]tetrahydrofiiran-2-yi]-5-[[(4-methoxyphenyl)-diphenyi-methyl]amino]-6H- thiazolo[4,5-(/]pyrimidine-2.7-dione (Composed lo-A) instead of Compound lo-B.

Example 1-A: MS obsd. (ESI ) [(M+H) ]: 356.1; Ή NMR (400 MHz, D SO-J,) δ ppm: 1.01 (t, J = 7.40 Hz.3H), 1.19 (d, J = 6.40 Hz, 3H), 1.43-1.63 (m.2H), 1.94-2.09 (m.111), 2.35 (ddd,J = 12.64,9.69, 6.02 Hz, 1H), 2.91-3.02 (m, 1 H), 3.10 (quin. J = 6.74 Hz, 1H), 3.48 (dt,J=8.50, 4.34 Hz, 1H), 4.03-4.15 (m.111), 6.07 (d, J= 6.78 Hz, IH).

Example 1-B: MS obsd. (ESI ) [(M + H) ]: 356.1; Ή NMR (400 MHz, DMSO-ίΛ,) δ ppm: 0.89 (t, J= 7.34 Hz, 3H) 0.97 (d, J= 6.27 Hz, 3H), 1.21-1.36 (m, IH), 1.37-1.56 (m, IH), 1.89-2.01 (m, IH).2.09-2.21 (m, IH), 2.82 (br. s., IH), 2.87-2.98 (m, IH), 3.80-3.90 (m, IH), 4.71 (br. s., IH), 5.83 (d, J= 5.77 Hz, IH), 7.09 (br. s., 2H).

Example 2

5-Amino-3-[(2«,3S,5S)-5-[ilS)-l-hydroxypropyl]-3-[(l_JR)-l- (methylamino)etliyl|tetrahydrofuran-2-yl|-6//-thiazolo|4,5-</| pyrimidine-2,7-dione

2

[( 1 S)- 1 -[(2/?,3S,5S)-5-[( 1 S)- 1 -[tt/Y-butyl(d iphenyl )silyl Joxypropyl ]-2-| 5-[ | (4- methoxyphenyl)-diphenyi-methyl] amino] -2,7-dioxo-6H-thiazolo [4,5- ]pyrimidin-3- y 1 j t c t ra h yd ro fu ra n - 3 - y 1 ] ethyl] methanesulfonate (Compound l!-B, 1.8 g, 1.9 mmol ) was dissolved in a solution of MeNH₂ in cthanol (33 wt.% in absolute ethanoi, 20.0 mL. 149 mmol ) and the reaction mixture was heated with stirring at 80 °C under N₂ for 20 hours. The reaction solution was cooled to 25 °C and concentrated in vacuo, and the residue was purified by column chromatography (elut ing with 0-2% methanol in DCM) to give 0.8 g of 3-[(2tf,3S,5S)-5-[( 1 S)- 1 - [te/ -butyl(diphenyl)silyl]oxypropyi]-3-[(li?)-l-(methyiamino)ethyi]tetrahydrofuran-2-yl]-5- [[(4-methoxyphenyl)-diphenyl-methyi]amino]-6H-thiazolo[4,5-i ]pyrimidine-2,7-dione

(Compound 2a) as a yellow solid.

Preparation of 3-| (2tf,3S,5S)-5-| ( IS)- 1 -hydroxy prop i|-3-| ( \ R)-l-

2b

A solution of 3-[(2/?,3S.5S)-5-[( 15)- 1 -[/m-butyl(diphcnyl )si]yl]oxypropyl]-3-[( 1 /?)- 1 - ( met h y 1 a m i no )et li y 1 ] t ct ra h yd ro furan-2-yl] -5 - [ [(4-methoxyphenyl)-diphenyl-methyl] amino] -6H- thiazolo[4,5-</]pyrimidinc-2,7-dione (Compound 2a, 1 .7 g, 2.0 mmol ) i n t ct rabu t y 1 a m mo n i u m fluoride (1M in THF, 10.0 mL, 10.0 mmol) was stirred at 50 °C for 16 hours. The reaction solution was diluted with water ( 50.0 mL ), extracted with DCM methanol ( 10: 1 , 100 mL ) twice. The combined organic layer was dried over anhydrous Na₂SC«4, filtered and concentrated in vacuo. The residue was purified by column chromatography (eluting with 0-5% methanol in DCM) to give 1 .0 g of 3-[(2/?.35,55)-5-[( 1 S)- 1 -hydroxy-propyl ]-3-[( 1 /?)- 1 - ( met h y la m i no )et h y 1 ] t et rah yd ro furan-2-yl] -5 - [[ (4-mcthoxyphenyl )-diphenyl-methyl ] amino] -6H- thiazolo| 4,5-(/jpyrimidine-2.7-dione (Compound 2b) as a yellow oil.

Preparation of 5-amino-3-[(2i?,3S,5S)-5-[(lS)-l-hydroxypropy!]-3-[(li?)-l- (mcthyIamino)cthyl|tetrahydrofuran-2-yl|-6//-thiaz()Io|4,5-i/| pyrimidinc-2,7-dionc

( Example 2)

2

A solut ion of 3-[(2R,35,5S)-5-[(lS)-l-hydroxypropyl]-3-[(lR)-l- ( methylamino)ethyl jtetrahydro furan-2-yl] -5 - [ [ (4-methoxyphenyl )-diphenyl-methyl j amino] -6H- thiazolo[4,5-d]pyrimidine-2,7-dione (Compound 2b, 1 .0 g, 1 .5 mmol ) in formic acid ( 10.0 mL) was stirred at 20-25 °C under N₂ for 20 minutes. The mixture was concentrated under reduced pressure and the residue was purified by preparative HPLC to give 0. 1 2 g of 5-amino-3- [(2/?,3S,5S)-5-[( 1 S)- 1 -hydroxypropyl]-3-[( \R)-\ -(mcthylamino)cthyl]tctrahydrofuran-2-yl]-6H- thiazolo[4.5-</]pyrimidinc-2.7-dione (Example 2) as a white solid.

Example 2: MS obsd. (ESI ) [(M+H)^']: 370.0; Ή NMR (400 MHz, Methanol-*/*) δ ppm: 1.001 (t, J= 7.40 Hz, 3H), 1.09 (d, J= 6.53 Hz, 3H), 1.42-1.64 (m, 2H), 2.06 (dt, J= 12.52, 7.92 Hz, 111), 2.37-2.43 (m, 111), 2.44 (s, 311), 2.74-2.87 (m, HI), 3.13-3.24 (m, 111), 3.47 (dt, J= 8.50, 4.34 Hz, HI), 4.03- 4.14 (m, 1H), 6.03 (d, J= 7.15 Hz, 1H).

Example 3

5-Amieo-3-[(2i?,3S,5S)-5-[(lS)-l-hydroxypropyl]-3-[(li?)-l- (propylamino)etliyll tetrahvdrofuran-2-yl| -6//-thiazolo |4,5-</| pyrimidine-2,7-dione

3

The title compound was prepared in analogy to Example 2, by using propylamine i of mcthylaminc. The final product was purified by preparat ive I I PLC and SFC to afford

Example 3 as a white solid.

Example 3: MS obsd. (ESI ) [(M+H)^']: 398.1; Ή NMR (400 MHz, Methanol-^) δ ppm: 0.95 (t, J= 7.40 Hz.311), 1.01 (t.J = 7.40 Hz, 3H), 1.13 (d, J = 6.4, 311), 1.33-1.61 (m, 411), 2.05 (dt, J = 12.36, 7.87 Hz, 1H), 2.42 (ddd, J= 12.55, 9.60, 6.09 Hz, 111), 2.58 (ddd, J = 11.45, 8.56, 6.46 Hz, IH), 2.67-2.77 (m.111).2.94 (quin. J= 6.74 Hz, 111), 3.17-3.28 (m.111), 3.49 (dt, J= 8.53, 4.39 Hz, HI), 4.03-4.14 (m.111), 6.05 (d, J= 6.90 Hz, 111).

Example 4

5-Amieo-3-[(2«,3S,5S)-3-[(li?)-l-(cyclopropy!amiiio)ethyl]-5-[(lS)-l- hydroxypropyl]teirahydrofiiran-2-yl]-6H-thlazolo[4,5-d]pyrimldliie-2,7-dioee

The title compound was prepared in analogy to Example 2, by using cyclopropylamine instead of methylamine. The final product was purified by preparative HPLC and SFC to afford Example 4 as a white solid. Example 4: MS obsd. (ESI ) [(M+H)^']: 396.1 ; Ή NMR (400 MHz, Met ha no !-</.,·) δ ppm: 0.51-

0.86 (m, 4H), 1.01 (t, .1 = 7.40 Hz, 3H), 1.28 (d, J= 6.02 Hz, 3H), 1.40-1.69 (m, 2H), 1.98-2.15 (m, 1H), 2.31-2.57 (m.2H), 3.25-3.37 (m, 211), 3.49 (dt,J= 8.66, 4.33 Hz, 1H), 3.97-4.16 (m, 1H), 6.06 (d. J =6.27 Hz, 1H).

Example 5

5-Amieo-3-[(2i?,3S,5S)-3-[(l«)-l-(beezj¾mieo)ethy!]-5-[(lS)-l- hydroxypropyl]tetrahydrofiiraM-2- l]-6H-thlazolo 4,5-iflpyrimldliie-2,7-dloiie

The title compound was prepared in analogy to Example 2, by using benzylamine instead of methylamine. The final product was purified by preparative HPLC and SFC to afford

Example 5 as a light yellow solid.

Example 5: MS obsd. (ESI ) [(M+H)^']: 446.1 ; Ή NMR (400 MHz, Methanol-^) δ ppm: 0.99 (t, J = 7.40 Hz, 3H), 1.14 (d,J= 6.40 Hz, 3H), 1.38 -1.64 (m, 2H), 1.87-2.09 (m, 1H), 2.38 (ddd, J = 12.30, 9.47, 6.71 Hz, 1H), 2.86 (t, J= 6.15 Hz, 1H), 3.14-3.27 (m, 1H), 3.47 (dt, J= 8.53, 4.39 Hz, IH), 3.73 (d,J= 13.05 Hz, 1H), 3.91 (d,J= 13.18 Hz, 1H), 3.98-4.07 (m, 1 H).6.07 (d, J = 6.53 Hz, 1H), 7.16-7.41 (m, 5H). Example 6

5-Amino-3-|(2/f^S^",5S>5-|(LS>l-hydroxypropyl|-3-|(LS>l-

(mcthylamino)ethyl|tetrahydrofuran-2-yl|-6//-thiazolo|4,5-</| pyrimidine-2,7-dione

6 The title compound was prepared in analogy to Example 2, by using Compound 11- A instead of Compound ll-B. The final product was purified by preparative HPLC to afford

Example 6 as a white solid.

Example 6: MS obsd. (ESI ) [(M+H)^']: 370.0; Ή NMR (400 MHz, Methanol-*/*) δ ppm: 1.01 (t, J= 7.47 Hz, 311), 1.16 (d, J= 6.53 Hz, 3H), 1.45-1.62 (m, 2H), 2.06 (dt, J= 12.58, 8.20 Hz, 1H), 2.24-2.31 (m, III), 2.34 (s, 311), 2.77 (quin, J= 6.40 Hz, 111), 3.17 (dt,J= 15.47, 7.64 Hz, 1 1), 3.41-3.53 (m, 1H), 4.01-4.16 (m, 111), 6.04 (d, J= 7.28 Hz, 1 1).

Example 7

The title compound was prepared in analogy to Example 5, by using Compound 11-A instead of Compound ll-B. The final product was purified by preparative HPLC to afford

Example 7 as a light yellow solid. Example 5: MS obsd. (ESI ) [(M+H)^']: 446.0; Ή NMR (400 MHz, Methanol-**) δ ppm: 1.01 (t, J= 7.47 Hz, 311), 1.40 (d, J= 6.53 Hz, 3H), 1.45-1.64 (m, 211), 2.09-2.20 (m, 111), 2.23-2.33 (m, 1H), 3.20 (m, 1H), 3.36-3.43 (m, 1H), 3.48 (dt, J = 8.31, 4.31 Hz, 1H), 4.01 (d, J = 4.1 1 (d, J= 13.2, 1H), 4.10-4.18 (m, 1H), 6.03 (d, J = 7.40 Hz, H ). 7.37 (s, 5H).

Example 8

5-Amino-3-[(2i?,3S,5S)-3-[(li?)-l cBmethy!ammo)ethy!]-5-[(lS)-l- hydroxypropyl|tetrahydrofuran-2-yl|-6//-thiazolo|4,5-</| pyrimidine-2,7-dione

8

Preparation of 3-[(2^,3S,5S)-5-[(lS)-l-[teri-butyl(dipheny!)sI!yl]oxypropyI]-3-[(l«)-l- (dlmethylamlno)ethyl]tetrahydrofnran-2-yl]-5-[[(4-methoxyphenyl)-diphenyI- methyl|amino|-6//-thiazolo|4,5-</| pyrimidine-2,7-dione (Compound 8a)

8a

To a solution of 3-[(2i?,3,S,55)-3-[(li?)-l-aminoethyl]-5-[(15)-l-[tert- butyl(dipiicnyi )silyl ]oxypropyl]tctraliydrofuraii-2-yl j-5-[ i i4-mctlio.xyphetiyl )-diphcnyl- methyl jamino]-6//-thiazolo[4,5-i/]pyrimidinc-2,7-dionc (Compound l n-B, 400.0 mg, 0.46 mmol ) in dichloroethanc (20.0 ml . ) was added s-trioxane (208.0 mg, 2.3 mmol ) and acet ic acid (30.0 mg, 0.456 mmol ). After the reaction mixture was stirred at 25 °C for 0.5 hour,

aBH(OAc); (293.6 mg, 1 .4 mmol ) was added. After addit ion, the reaction mixture was stirred at 25 °C for another 12 hours, and then filtered and the filtrate was concentrated in vacuo. The residue was purified by column chromatography (eluting with 10-30% ethyl acetate in petroleum ether, and then 1% methanol in DCM) to give 400.0 mg of 3-[(2/?,35,55)-5-| ( 1 S)- 1 -\terr- butyl(diphenyl)silyl]oxypropyl] -3 - [( li?)- 1 -(dimethylamino)ethyl]tetrahydrofuran-2-yl] -5 - [[(4- methoxyphenyl)-diphenyl-methyi]amm^ (Compound 8a) as a yellow solid.

8b

A solution of 3-[(2R,3S,5iS)-5-[(liS)-l-[tert-butyl(diphenyl)silyl]oxypropyl]-3-[(lR)-l-

(dimethylamino)ethyl]tetrahydro furan-2-yl] -5 - [[(4-methoxyphenyl)-diphenyi-methyi] amino] - 6H-thiazolo[4,5-c/]pyrimidine-2 J-dione (Compound 8a, 0.4 g, 0.46 mmol) in

tetrabutyiarnmonium fluoride (3M in THF, 10.0 ml) was stirred at 50 °C for 12 hours. The reaction solution was diluted with water (20.0 ml), extracted with ethyl acetate (20 niL) twice. The combined organic layer was dried over anhydrous Na₂S0₄, filtered and concentrated under reduced pressure. The residue was pu ified by column chromatography (elut ing with 10-30% ethyl acetate in petroleum ether) to give 2 1 0.0 mg of 3-[(2R,35,5S)-3-[(lR)-l-

( d i met h via m i no )et h y I ] -5 - [( 15)- 1 -hydro xypropyi]tetrahydrofuran-2-yl] -5 - [ [(4-methoxyphenyl)- diphcnyl-methyl]amino ]-6/7-thiazolo[4.5-J]pyrimidine-2.7-dione (Compound 8b) as a yellow solid.

Preparation of 5-amino-3- [(2R,3S,5S}~3- |( l /?)-l -(dimethyiamino)ethyl| -5- |( LS>1 - hydro ypropyl|tetrahydrofuran-2-yl|-6//-thiaAoIo|4,5-</| pyrimidine-2,7-dione (Example 8)

8

A solution of 3-[(2i?,35,55)-3-[(li?)-l-(dimethylam

hydroxypropyl]tetrahydrofuran-2^

thiazolo[4,5-J]pyrimidine-2,7-dione (Compound 8b, 200 mg, 0.49 mmol ) in formic acid (5.0 ml. ) was stirred at 20-25 °C under N₂ for 30 minutes. The mixture was concentrated in vacuo and the residue was purified by preparative HPLC to give 25.2 mg of 5-amino-3-[(2/?,3 S, 55 ) - 3 - [( IK)- 1 -(dimethyl a m i n o ) e t h y 1 ] -5-[ ( 15)- 1 -hydro xypropyljtetrahydro furan-2-yl] -6H-thiazo io [4,5 - (/jpyrim id ine-2,7-d ione ( Example 8 ) as a light yellow solid.

Example 8: MS obsd. ( ESI ) [( M+ H ) ]: 384.1 ; Ή MR (400 MHz, Methanol-^) δ ppm: 0.87 (d, J= 6.40 Hz, 3H), 1 .00 (t, J= 7.59 Hz, 3H), 1 .5 1 (m, 2H), 2.22 (m, 7H), 2.3 1 -2.41 (m, 1H), 2.67 (m., 1H), 3. 1 7-3.25 (m, 1H), 3.48 (m, 1H), 4.02 (m, 1H), 5.95 (d, J = 7. 1 5 Hz, 1H).

Example 9

H EK293-Bliie-hTLR-7 eells assay: A stable HEK293-Blue-hTLR-7 cell line was purchased from InvivoGen (Cat.#: hkb-htlr7,

San Diego, California, USA ). These cells were designed for studying the stimulat ion of human TLR7 by monitoring the activat ion of F- Β. A SEAP (secreted embryonic alkaline phosphatase) reporter gene was placed under the control of the IFN-β minimal promoter fused to five NF-KB and AP- 1 -binding sites. The SEAP was induced by activat ing NF-κΒ and AP- 1 via st imulat ing HEK-Blue hTLR7 cells with TLR7 ligands. Therefore the reporter expression was regulated by the NF-KB promoter upon stimulation of human TLR7. The cell culture supernatant SEAP reporter activity was determined using QUANTI-Biue™ kit (Cat.#: rep-qb 1 , Inv ivogcn, San Diego, Ca, USA) at a wavelength of 640 nm, a detection medium that turns purple to blue in the presence of alkaline phosphatase. HEK293-Blue-hTLR7 cells were incubated at a density of 250,000-450,000 cells/mL in a volume of 180 μ L in a 96-well plate in Dulbecco's Modified Eagle's medium (DMEM) containing 4.5 g/L glucose, 50 U/mL penicillin, 50 mg/mL streptomycin, 100 mg/mL Normocin. 2 mM L-glutamine, 10% (v/v) heat-inactivated fetal bovine serum for 24 hours. Then the

H E K 293 - B 1 u e- h i^' L R - 7 cells were incubated with addit ion of 20 μ L test compound in a serial dilution in the presence of final DMSO at 1% and perform incubation under 37 °C in a CO 2 incubator for 20 hours. Then 20 μ L of the supernatant from each well was incubated w ith 180 μ L Quant i-bluc substrate solution at 37 °C for 1 -3 hours and the absorbance was read at 620-655 nm using a spectrophotometer. The signalling pathway that TLR7 activat ion leads to downstream NF-KB act ivat ion has been w idely accepted, and therefore similar reporter assay was also widely used for evaluating TLR7 agonist (Tsuneyasu Kaisho and Takashi Tanaka, Trends in

I mmunology, Volume 29, Issue 7, July 2008, Pages 329. sci; Hiroaki Hem mi et al, Nature I mmunology 3, 2002, 1 96 200. ).

H E 293-Blue-hTLR-8 cells assay: A stable HEK293-Blue-hTLR-8 cell l ine was purchased from InvivoGen (Cat.#: hkb-htlrS,

San Diego, California, USA). These cells were designed for studying the stimulat ion of human TLR8 by monitoring the activat ion of NF-κΒ. A SEAP (secreted embryonic alkaline phosphatase) reporter gene was placed under the control of the IFN-β minimal promoter fused to five NF-KB and AP- 1 -binding sites. The SEAP was induced by activat ing NF-κΒ and AP-1 via st imulat ing HEK-Blue I1TLR8 cells with TLR8 !igands. Therefore the reporter expression was regulated by the NF-KB promoter upon stimulation of human TLR8. The ceil culture supernatant SEAP reporter activity w as determined using QUANTI-Blue™ kit (Cat.#: rep-qb l , Invivogen, San Diego, Ca, USA) at a wavelength of 640 nm, a detection medium that turns purple to blue in the presence of alkaline phosphatase. HEK293-Blue-hTLR8 ceils were incubated at a density of 250,000-450,000 cells/mL in a volume of 1 0 u L in a 96-well plate in Dulbecco's Modified Eagle's medium ( DMEM ) containing 4.5 g/L glucose, 50 U/mL penicillin, 50 mg/mL streptomycin, 1 00 mg/mL Normocin, 2 mM L-glutamine, 10% (v/v) heat-inactivated fetal bovine serum for 24 hours. Then the

HEK293-Blue-hTLR-8 ceils were incubated with addition of 20 μ L test compound in a serial dilut ion in the presence of final DMSO at 1 % and perform incubat ion under 37 °C in a CO 2 incubator for 20 hours. Then 20 μ L of the supernatant from each well was incubated w ith 1 80 μ L Quanti-bluc substrate solution at 37 °C for 1 -3 hours and the absorbance was read at 620-655 nm using a spectrophotometer. The signalling pathway that TLR8 activation leads to downstream NF- B activation has been widely accepted, and therefore similar reporter assay was also widely used for evaluat ing TLR8 agonist. The compounds of the present invention were tested in the above assay for their TLR7 and

TLR8 agonism activities as described herein and results are listed in Table 1. The Examples were found to have EC 5₀ of TLR7 agonism activities about 3 iiM to about 250 μΜ and TLR8 agonism activities about 1 iiM to about 190 μΜ. Particular compounds of formula (I) or (la) were found to have E \₀ of TLR7 agonism activities about 3 μΜ to about 100 μ M and TLR8 agonism activities about 1 μ M to about 100 M.

Table 1: Activity of Compounds in HE 293- liTLR-7 and HEK293-h I LR-8 assay:

Example No. HEK293- hTLR-7 EC50 (μΜ) HEK293- hILR-8 EC 50 (μΜ)

1-A 75 1.3

1-B 101 55

2 81 27

3 7.7 125

4 3.5 94

5 3.7 85

6 250 4

7 3.4 2.2

8 82 185

Claims

1. A compound of formula (I),

wherein

R¹ is H, C| .alkyl,

said pheiiylCi ,alkyl being unsubstituted substituted with one to three substituents independently selected from Ci <,aikyl and halogen;

R is I I or C ,alkyk

R³ is C.alkyl;

R⁴ is C.alkyl;

or pharmaceutically acceptable salt, enantiomer or diastereomer thereof.

2. A compound of formula (la) according to claim 1,

wherein

R¹ is H, C| .₍₁alkyl, C; -cycloalkyl or phenylCi <,alkyl, said phenylCi <,alkyl being unsubstituted or substituted with one to three substituents independently selected from C .alkyl and halogen;

R³ is Ci,,alkyl; R⁴ is Ci_₆alkyl;

or pharmaceut ically acceptable salt, enantiomer or diastereomer thereof.

3. A compound according to claim 1 or 2, wherein

R¹ is H, methyl, propyl, cyclopropyl, benzyl, fluorobenzyl. chlorobenzyl, 11 uo roc h lo robenzy 1 or methylbenzyl;

R is H or methyl;

R³ is methyl;

R⁴ is ethyl;

or pharmaceutically acceptable salt, enantiomer or diastereomer thereof.

4. A compound according to any one of claims 1 to 3, wherein R¹ is H, C .alkyl or phenylCi. (,alkyl; or pharmaceutically acceptable salt, enantiomer or diastereomer thereof.

5. A compound according to any one of claims 1 to 4, wherein R¹ is H, methyl or benzyl; or pharmaceut ically acceptable salt, enant iomer or diastereomer thereof

6. A compound according to any one of claims 1 to 5, wherein R is H; or pharmaceut ically acceptable salt, enant iomer or diastereomer thereof.

7. A compound according to any one of claims 1 to 6 selected from:

5-Amino-3-[ (2/?.3S,5S)-3-| ( 1 S)- 1 -aminoethyl ]-5-| ( 1 S)- 1 -hydroxypropyl ]tetrahydrofuran-2-yl j- 6//-thiazolo[4,5-(/]pyrimidine-2,7-dione;

5-amino-3-| (2/?.3S,5S)-3-[ ( \ R )- \ -aminoethyl ]-5-[( 1 S)- 1 -hydroxypropyl]tetrahydi furan-2-yl]- 6/7-thiazolo[4,5-(/]pyTimidine-2,7-dione;

5-Amino-3-[ (2 ?,35,5S)-5-[( 1 S)- 1 -hydroxypropyl ]-3-[( 1 )- 1 -

(methylamino)ethyl]tetrahydrofuran-2-yi]-6H-thiazolo[4,5-</Jpyrimidine-2,7-dione;

5-Amino-3-[(2i?,3₁S,55)-5-[(l₁S)-l-hydroxypropyi]-3-[(li?)-l- (propyiamino)ethyi]tetrahydrofuran-2-yl]-6H-thiazolo[4,5-<i]pyrimidine-2,7-dione; 5-Amino-3-[(2/?.3S,55)-3-[( 1 /?)- 1 -(cyclopropylamino )ethyl ]-5-[ ( 1 S)- 1 - hydro xypropyi]tetrahydrofuran-2-yi]-6H-thiazolo[4,5-d]pyrimidine-2,7-dione;

5-Amino-3-[ (2/?.3S,5S)-3-[ ( \ R )- \ -( benzylamino )ethyl ]-5-[ ( 15)- 1 - hydro ypropyl]tetrahydrofuran-2-yi]-6H-thiazoio[4,5-J]pyrimidine-2,7-dione; 5-Amino-3-[(2/?,3S,5S)-5-[( 1 S)- 1 -hydroxypropyll-3-[( 1 S)- 1 - (methylamino)ethyl]tetrahyd^

5-Amino-3-[(2/ S,5.S^')-3-[( 1 /0- 1 -(benzylamino )ethyl]-5-[ ( 1 S)- 1 - liydroxypropyl]tctraliydrofiiran-2-yl]-6//-thiazolo[ 4,5-J]pyTim id i and 5-Amino-3-[(2/US,5S)-3-[ ( \ R )- \ -(dimcthylamino )ethyl]-5-[ ( 1 S)- 1 - hydro xypropyl]tetrahydroforan-2-yl]-6H-tMazolo[4,5-<i]pyrimidine-2,7-dione; or pharmaceutically acceptable salt, enantiomer or diastereomer thereof.

8. A process for the preparation of a compound according to any one of claims 1 to 7 comprising the following steps:

(a) the reaction of a compound of formula ( I l lk),

with an acid;

(b) the reaction of a compound of formula (IV c),

with an acid, wherein ^a is R¹ or R

(c) the react ion of a compound of formula

with an acid, wherein R^h is C ,alkyl: or wherein R^a, R^b, R³, R⁴ are defined as in any one of claims 1 to 8.

9. A compound or pharmaceutically acceptable salt, enantiomer or diastereomer according to any one of claims 1 to 7 for use as therapeutically act ive substance.

10. A pharmaceutical composition comprising a compound in accordance with any one of claims 1 to 7 and a therapeutically inert carrier.

1 1 . The use of a compound according to any one of claims 1 to 7 for the treatment or prophylaxis of hepatitis B virus infection.

12. The use of a compound according to any one of claims 1 to 7 for the preparation of a medicament for the treatment or prophylaxis of hepatit is B virus infect ion.

13. The use of a compound according to any one of claims 1 to 7 as the TLR7 or TLR8 agonist.

14. The use of a compound according to any one of claims 1 to 7 as the TLR7 and TLR8 dual agonist.

1 5. The use of a compound according to any one of claims 1 to 7 to induce production of interferon-a.

16. A compound o pharmaceutically acceptable salt, enant iomer or diastereomer according to any one of claims 1 to 7 for the treatment or prophylaxis of hepatitis B virus infection.

1 7. A compound or pharmaceutically acceptable salt, enantiomer or diastereomer according to any one of claims 1 to 7, when manufactured according to a process of claim 8.

18. A method for the treatment or prophylaxis of hepatitis B virus infection, which method comprises administering a therapeutically effective amount of a compound as defined in any one of claims 1 to 7.

1 9. The invent ion as hereinbefore described.